I started on Dark Age of Camelot.
Followed my guild on world of warcraft beta but prefered to go back to the european release of city of heroes after having tasted its awesomness on beta.
When I became bored I went to my guild in wow but most had left and came back to CoH again - felt bored again just a bit after cov release so I don't know most of the things after and I thank all the players on the help channel.
I played many other mmos : warhammer online (love the universe), star wars the old republic (love the "pet" companions), Rift (love what you can do with your classe / choose your specs), Aion (beurk : vomit), Guild Wars 2 (was ok).
And many other free to play. Special mention to deceased Marvel Heroes which I consider what Diablo 3 (beurk too) should have been - but hey maybe someone did what they did with CoH ? (with disney though I don't think the same will happen)
i don't know why but CoH and Marvel Heroes are where I've had my best memories even though I'm a medieval fantasy fan. The players (especially on CoH) are awesome.